Increase LOCKDEP_CIRCULAR_QUEUE_BITS to avoid this warning: ------------[ cut here ]------------ lockdep bfs error:-1 WARNING: kernel/locking/lockdep.c:2059 at print_bfs_bug+0x20/0x40 kernel/locking/lockdep.c:2059, CPU#1: kworker/u8:37/7279 Modules linked in: CPU: 1 UID: 0 PID: 7279 Comm: kworker/u8:37 Not tainted syzkaller #0 PREEMPT_{RT,(full)} Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound linkwatch_event RIP: 0010:print_bfs_bug+0x22/0x40 kernel/locking/lockdep.c:2059 Code: 90 90 90 90 90 90 90 90 55 53 89 fb e8 07 ce dd 02 89 c5 e8 60 84 ff ff 85 ed 74 13 83 fb ff 74 16 48 8d 3d e0 e4 40 0d 89 de <67> 48 0f b9 3a 5b 5d c3 cc cc cc cc cc 48 c7 c7 87 16 f3 8c e8 e5 RSP: 0018:ffffc900053af030 EFLAGS: 00010046 RAX: 000000000000003b RBX: 00000000ffffffff RCX: 4744a23242d4f200 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8ede4ac0 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52000a75da9 R12: ffffffff9566ef48 R13: ffffffff926d4298 R14: ffff8880252e1e40 R15: 000000000000001b FS: 0000000000000000(0000) GS:ffff888126e03000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fcabb4adf98 CR3: 0000000034856000 CR4: 00000000003526f0 Call Trace: check_irq_usage kernel/locking/lockdep.c:-1 [inline] check_prev_add kernel/locking/lockdep.c:3169 [inline] check_prevs_add kernel/locking/lockdep.c:3284 [inline] validate_chain kernel/locking/lockdep.c:3908 [inline] __lock_acquire+0x2551/0x2cf0 kernel/locking/lockdep.c:5237 lock_acquire+0x117/0x340 kernel/locking/lockdep.c:5868 _raw_spin_lock_nested+0x32/0x50 kernel/locking/spinlock.c:378 raw_spin_rq_lock_nested+0x2a/0x140 kernel/sched/core.c:639 raw_spin_rq_lock kernel/sched/sched.h:1558 [inline] task_rq_lock+0xbc/0x470 kernel/sched/core.c:739 class_task_rq_lock_constructor kernel/sched/sched.h:1858 [inline] migrate_disable_switch kernel/sched/core.c:2350 [inline] __schedule+0x1673/0x50a0 kernel/sched/core.c:6749 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7140 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x340 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] __local_bh_disable_ip+0x2fb/0x530 kernel/softirq.c:174 local_bh_disable include/linux/bottom_half.h:20 [inline] spin_lock_bh include/linux/spinlock_rt.h:87 [inline] dev_reset_queue+0xf4/0x1f0 net/sched/sch_generic.c:-1 netdev_for_each_tx_queue include/linux/netdevice.h:2680 [inline] dev_deactivate_many+0x71f/0xd40 net/sched/sch_generic.c:1374 dev_deactivate+0x118/0x1b0 net/sched/sch_generic.c:1397 linkwatch_do_dev+0x10f/0x170 net/core/link_watch.c:184 __linkwatch_run_queue+0x56d/0x7e0 net/core/link_watch.c:244 linkwatch_event+0x4c/0x60 net/core/link_watch.c:304 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 ---------------- Code disassembly (best guess): 0: 90 nop 1: 90 nop 2: 90 nop 3: 90 nop 4: 90 nop 5: 90 nop 6: 90 nop 7: 90 nop 8: 55 push %rbp 9: 53 push %rbx a: 89 fb mov %edi,%ebx c: e8 07 ce dd 02 call 0x2ddce18 11: 89 c5 mov %eax,%ebp 13: e8 60 84 ff ff call 0xffff8478 18: 85 ed test %ebp,%ebp 1a: 74 13 je 0x2f 1c: 83 fb ff cmp $0xffffffff,%ebx 1f: 74 16 je 0x37 21: 48 8d 3d e0 e4 40 0d lea 0xd40e4e0(%rip),%rdi # 0xd40e508 28: 89 de mov %ebx,%esi * 2a: 67 48 0f b9 3a ud1 (%edx),%rdi <-- trapping instruction 2f: 5b pop %rbx 30: 5d pop %rbp 31: c3 ret 32: cc int3 33: cc int3 34: cc int3 35: cc int3 36: cc int3 37: 48 c7 c7 87 16 f3 8c mov $0xffffffff8cf31687,%rdi 3e: e8 .byte 0xe8 3f: e5 .byte 0xe5